and begin with the latest in the jessica ridgeway case. Austin reed sigg has confessed to the killing of the colorado girl after he was turned in by his mother. Clayton sandell has the story. Reporter: Two mothers on opposite sides of the same horrific crime, on thursday, came face-to-face. Sara ridgeway came to court to see the teenager police say killed her 10-year-old daughter, jessica, austin sigg. Just a few feet away, austin's mother, mindy. I didn't see eye contact on the sigg side. Reporter: Cameras and sketch artists were not allowed in court. But abc producer phillip mavavea was behind jessica's family. They didn't have emotion towards the sigg group. Reporter: Prosecutors will charge sigg as an adult. During the hearing, they dropped two bombshells. Telling a judge, sigg confessed to ridgeway's murder, as well as an attempted abduction in may. And they had dna evidence tying him to the backpack and the crime scenes. Defense attorney will point to procedural error and will try to undercut the reliability of the dna evidence. Reporter: Sigg's first court appearance came as investigators worked a second day at his westminster, colorado home. Sources tell abc news, human remains believed to be jessica's were found inside. Austin functions at a different reality, perhaps, than the rest of us. Reporter: Investigators are now combing through sigg's past. Looking for clues, even in old youtube videos like this. You can here sigg raving about his favorite, new band. Just give all in the praise in the world to for his album, "sound of faith." Sigg was enrolled in a nearby community college, studying mortuary science. I felt he was very intelligence. But just those -- I don't know. I can't explain it. It's creepy. Reporter: Sigg's parents are divorced. Overnight, his father, rob, spoke out for the first time to the ridgeway family and to his ex-wife, who called police on her own son. There are no words to express the sorrow that I and my family feel for their pain, his statement says. I also ask for your prayers and support for austin's mother, whose courageous act has put this tragedy on the path to resolution. For "good morning america," clayton sandell, abc news, colorado.

This transcript has been automatically generated and may not be 100% accurate.

Jessica Ridgeway's Alleged Killer Austin Reed Sigg

Marisa Randazzo discusses the suspect in the killing of a 10-year-old Colorado girl.